Vibrator transformer and rectifier



April 12, 1938. s. F. JAMES- VIBRAT QR TRANSFORMER AND RECTIFIER 2 Sheets-Sheet 1 Filed April 3, 1953 h E M m H L l I W a. .6 R o .u MW mm \H M :C I I 5 N 1. M 2 fi T lo $11.3

AprillZ, 1938. s. F. JAMES VIBRATOR TRANSFORMER AND RECTIFIER 2 Sheets-Sheet 2 Filed April 5, 1953 aim ufiofn Q55.

In \I c nTo Patented Apr. 12, 1938 UNITED STATES PATENT OFFICE vmna'ron TRANSFORMER AND momma Stephen F. James, 0mm, m.

Application April 3, 1933, Serial No. mm

19 Claims.

My invention relates to vibrator transformers and rectifiers and particularly to an arrangement designed for me primarily for supplying plate current for an automobile radio, preferably from the regular starting and ignition battery of the car. It is the object of my invention to pro ide a new and improved form and arrangement of parts by which an armature member may be given a more positive movement for effecting the desired making and breaking of the primary circuit of the transformer and whereby there shall be an increased effectiveness of such make and break mechanism and a correspondingly increased eifectiveness of the transformer action. To this end, it is one of the objects of my invention to provide an arrangement in which oscillation may be suppressed in the primary for cutting down the peaks of the potential at the times when the primary circuit is broken. It is another object of my invention to provide a device of this type in which the vibrator shall operate smoothly and at such high frequency as to prevent a change in the polarity of the armature from that initially set up in the armature.

It is one of the objects of my invention to provide an improved construction of this type in which themovement of the armature oi the vibrator is effected either principally or entirely by auxiliary fields set up by the use of auxiliary coils mounted either on portions of the core of the transformer or on other core parts in operative relation to the armature. It is one of the objects of my invention to provide an improved arrangement of cooperating coils for producing the operating field within the core of the transformer and for producing an auxiliary field or fields whereby the desired energization of the transformer and the desired movement of the armature may be effected, the arrangement preferably comprising make and break contact mechanism or other switching means controlled by the movement of the armature for making the necessary changes in the circuit connections for bringing about the desired transformer action and concurrent rectification in cases where rectification is desired.

It is 'one of the objects of my invention to provide an arrangement of this type in which the armature is pivoted at an intermediate point and is given its swinging movement by the joint effect of magnetically operating parts at both ends, the end portions of the armature being formed of magnetic material and having preferably a magnetic connection with each other so that normally there shall be opposite polarity at opposite ends of the armature, the arrangement preferably being such that the armature may be vibrated at sufficiently high frequency to prevent a change of polarity in the armature from that initially set up therein, the end portions of the armature being adapted normally to stand yieldingly in such position as to insure that the desired initial polarity shall be established in the armature at the start of operation.

It is another object of my invention to improve devices of this type in sundry details hereinafter pointed out. The preferred means by which I have accomplished 'my several objects are illustrated in the accompanying drawings and are hereinafter specifically described. That which I believe to be new and desire to cover by Letters Patent is set forth in the claims.

In the drawings,-

Fig. 1 is a diagrammatic view of one preferred form of my improved arrangement in which the auxiliary fields for effecting the movements of the armature are produced in the core of the transformer and in which the coils by which such auxiliary fields are produced are connected in series with the coils by which the principal field is produced in the transformer core;

Fig. 2 is a ditic view of another arrangement in which the fields by which the armature is moved are produced in core pieces separate from'the core of the transformer;

Fig. 3 is a diagrammatic view of an arrangement similar to that shown in Fig. 2 but involving the use of a double vibrator mechanism which serves to effect both a transformer action and a rectification of the secondary current from the transformer without the use of thermionic valves;

Fig. 4 is a diagrammatic view of an arrangement similar to that shown in Fig. 1 but having the auxiliary coils connected in parallel relation to the primary coils of the transformer;

Fig. 5 is a diagrammatic view of an arrangement similar to that shown in Fig. 1 but having the auxiliary coils connected in a different cooperating relation to the primary coils of the transformer; and

Fig. 6 is a top plan view of the armature and the parts carried thereby as shown in Fig. 1.

Referring now to Fig. 1 of the drawings, in indicatm a shell type of transformer core having primary coils i i and I2 mounted upon the central leg of the core and wound in reverse directions with respect to the lead 13 bywhich said coils are connected to a battery It. In its upper edge, the core It is provided with notches I5 and l5a prol1 respectively upon which are mounted coils l8 and I8 respectively.

Upon the upper face of the core I0, I have pivotally mounted an armature 20 formed of magnetic material and arranged to swing toward the arm portions I6 and I1 alternatively. Upon the armature 20, I have provided resilient bars 2| and 2|a preferably of brass, forming a support for resilient bars 22 and 22a also preferably formed of brass, bars 23 and 23a being mounted above the bars 22 and 22a, said boss 23 and 2311 being preferably formed of commercial tin plate. At opposite end portions of the armature 20, I have provided thin collars 20a of copper about the armature opposite the notches l5 and l5a. The arrangement is such that the bars 2|, 22 and 23 and the bars 2|a, 22a, and 23a are adapted to vibrate with the armature 20, the device as a whole being balanced so as to per mit ready movement of the device in opposite directions. A light spring 24 carried by the armature 20 holds the armature and its connected parts normally in the position as shown in the drawings, the effective strength of thespring 24 being adjustable by the use of a set screw 24a adjustably mounted in a standard 24b.

The brass bars 22 and 22a carry at their ends contact members 25 and 26 respectively preferably of silver, such contacts 25 and 26 being adapted to engage set screws 21 and 28 respectively upon the vibration of the armature 20, such set screws 21 and 28 being adjustably mounted in standards 29 and 30 and being provided with contact portions at their ends formed of tungsten:

In the arrangement shown, the coils I I and Hi are connected together by a lead 3|; the coil I8 is connected with the standard 29 and the set screw 2'! by a lead 32; and the bars 22 and 22a are connected with the battery l4 by a lead 33, having a switch 34 interposed therein. At the opposite side, the coil I2 is connected with the coil l9 by a lead 35 and said coil !9 is connected with the standard 3|] and the set screw 28 by a lead 36. A by-pass condenser 31 is connected across the switch comprising the contacts 25 and 21 at the left, and a bypass condenser 38 is connected across the switch comprising the contacts 25 and 28 at the right. The set screws 21 and 28 are further connected by a by-pass condenser 39. In the arrangement shown, the condensers 31 and 38 are of approximately one-tenth of a microfarad capacity each, while the condenser 39 is of approximately one-half of a microfarad capacity.

Upon the central leg of the core I0, I have provided secondary coils 40 and 4| reversely wound with respect to the lead 42 to which said coils are connected. The coils 40 and 4| are further connected by means of leads 43 and 44 with the plates of thermionic valves 45 and 46 respectively. The filaments of the valves 45 and 46 are connected by means of leads 41 with coils 48 and 49 respectively wound upon the central leg of the transformer in reverse direction with respect to the common lead 41. A lead 50 connected with the filament circuit 41 is connected with the lead 42 by means of condensers 5| and 52, the lead 42 between the points of connection of the condensers 5| and 52 therewith comprising a choke coil 53, the condensers BI and 52 and the choke coil 53 constituting an eifective filter for smoothing the current through the output leads 42 and 50.

viding upwardly projecting arm portions l6 and With the parts in the condition as shown in Fig. 1, when the switch 34 is closed, a current from the battery I4 is sent through the coil l2 and the coil IS, the arrangement of the parts being such that said coils by the effect of the current therethrough tend to produce the same polarity in the arm portion ll of the core. The current through the coil l2 at the same time produces the same polarity in the arm portion l6, but the field conditions in the arm H are considerably stronger by the influence of the two coils than those in the arm "5 through the influence of the coil |2 alone. The bar 20 is therefore magnetized, producing a pole opposite the arm ll of reverse polarity as compared with that of the adjacent end of the arm I! and producing a polarity opposite the arm I6 corresponding to that of the adjacent and of said arm IS. The armature 20 is, therefore, attracted by the strong field in the arm I! and repulsed by the field in the arm l6, causing the armature to swing in clockwise direction in said Fig. 1 so as to open the circuit at the contact 26 and to close the circuit at the contact 25. In view of the provision of the condenser 38 across the contacts 26 and 28, the polarity of the core I0 as a whole is quickly changed by reason of the reverse induced current through the coil l2, supplemented by the battery current through the coil II when the circuit is closed at the contact 25. Such reversed polarity in. the arm portion I6 is reenforced by the action of the coil l8 which is connected in cooperative relation with the coil l.|.

The result is that a strong field is very quickly established in the arm portion I6 serving very effectively to attract the end of the armature 20 at the left, such action being effective before the magnetic field has had time to change in the armature 20. The attraction between the arms l6 and the armature at the left is opposed by a repulsion effect between the arm I! and the end of the armature at the right, but since the magnetic field is much stronger in the arm I 6 than it is in the arm H, the armature 20 is swung quickly in counter-clockwise direction so as to return the armature to the position as shown in the drawings. The following action is the same as that above described upon the initial stroke of the armature 20, except that upon strokes subsequent to said initial stroke the field conditions in the arm l6 are substantially strengthened by the action of the reverse induced current through the coil l8 due to the breakage of the battery circuit between the contacts 25 and 21 serving more strongly to repel the armature at the left.

It is believed to be unnecessary to describe in detail the effect of the circuit comprising the secondary coils 40 and 4|. As will be readily understood, when the field conditions in the core III as a whole are reversed upon the vibration of the armature 20, secondary induced currents are set up alternately in the coils 40 and 4|, which at some other unprotected point so as to cause ansaea damage and ultimately interfere with proper operation oi. the vibrator unit.

In the arrangement shown in 18g. 2. a core Ila is employed in lieu of the, core 18, the central leg of which is provided with coils II and II as above described and with coils 48 and 4|. Coils 54 and 55 are employed in lieu of coils II and H, such coils 54 and 55- being mounted upon pole pieces 55 and 51 respectively formed separately from the corella. In the arrangement shown in Fig. 2, the filaments of the valves 45 and 48 are heated by current from a separate battery 58 through leads 58a in lieu of being heated through the medium of secondary coils on the core of the transformer, the output lead 58 being connected with one of said leads 580. Contact pieces 25a and 28a of tungsten are substituted in lieu of the contacts 25 and 26 of Fig. 1, and the set screws 21a and 280. are provided with contact points of molybdenum in lieu of tungsten as shown in Fig. 1. In the arrangement as shown the copper collars 28a are omitted, but such collars can be used if desired. Bars 21b, 22b and 28b are substituted for the two sets of bars as used in Fig. 1, the contact pieces 25a and 28a. being mounted on opposite end portions of the bar 22b.

In the operation of the device as shown in Fig. 2, the' armature 28 is actuated entirely by the fields set up in the core parts 56 and 51 independently of the field conditions in the core 5811. When the switch 84 of the arrangement in Fig. 2 is closed, a field is set up in the core part 51 serving to polarize the armature 28 and to move the armature in clockwise direction for opening the circuit at the contacts 28a and 28a and to close the circuit at thecontacts 25a and 21a. Upon the opening of the circuit between the contacts 260 and 28a, a reverse induced current through the coil 55 serves quickly to reverse the field in the core part 51 so 'as to cause a repulsion between the core part 51 and the armature 20. At the same time the battery current through the coil 54 serves to attract the armature at the left, the fields in the core parts 56 and 51 thus cooperating for moving the armature 28 in counterclockwise direction into the position as shown in said Fig. 2. The frequency of movement of the balanced armature 20 is such that the polarity of the armature 20 remains the same throughout the operation, in contrast to the quickly changing magnetic conditions within the core parts 56 and 51 by the action of the condensers 31 and 38.

I have found in practice that when my invention is used for producing fairly heavy currents, such as are used in connection with neon signs, the tungsten and molybdenum contacts work to better advantage than the silver and tungsten contacts as employed in the Fig. 1 construction. The silver and tungsten contacts are however preferable for producing plate current for radio use.

In thearrangement shown in Fig. 3, the construction is substantially the same as that shown in Fig. 2, except that the valves 45 and 46 are eliminated in Fig. 3 and additional switch means is provided for taking the place of the valves for effecting the desired rectification. In the arrangement shown in Fig. 3, the parts are given the same reference characters as are used in Fig. 2 so far as such parts correspond. In the device of Fig. 3, additionalcontacts 59 and 68 are mounted upon opposite end portions of the bar 22b, each of such contacts being insulated from the bar 22b by means of blocks 61. Set screws 82 and 88 mounted in standards 84 and 88 respectively are adapted to engage the contacts 58 and 88 alternatively for breaking the circuits through such cooperating contacts in the same timed relation as that of the breaking of the circuits through the contacts 25 and 21 and the contacts 28 and 28.

In the arrangement shown in said Fig. 3, the secondary coil 48 is connected by a lead 56 with the standard 84 and the set screw 82, and the contacts 58 and" are connected together by a lead 81 which is extended to serve with the lead 42 as one of the output'leads oi the transformer. In this device, the armature 20 is provided with short-circuiting collars 28a of copper opposite the ends of the pole-pieces 58 and 51 corresponding to the collars 20a as shown in Fig. 1.

When the switch 34 of the mechanism as shown in Fig. 3 is closed, the armature 28 is vibrated in the same manner as is above described in connection with Fig. 2. The arrangement of the circuits and the contacts is such in said Fig. 3 that when the circuit is complete through the coils II and 54 through the medium of the contacts 21a and 25a, the secondary circuit is complete through the coil 48 and the contacts 59 and 62; and such that when the circuit is complete through the primary coil l2 and the coil 55 through the medium of the contacts 28a and 25a the secondary circuit is complete through the coil 4| and the contacts 88 and 60. when the circuit is broken at the left through the primary circuit comprising the coil II, a high tension secondary current is sent through-the coil 40 in one direction. When the circuit through the primary coil 12 is broken, a high tension secondary current is sent through the coil 41 in the opposite direction. Thus a' unidirectional flow is established in the output leads 42 and 61 as is desired for use in connection with the plates of a radio. The collars 28a have the same short-circuiting eiIect as above described in connection with Fig. 1.

The arrangement shown in Fig. 4 is of the same type as that shown in Fig. 1. Coils 68 and 89 are substituted on the arm portions 16 and 11 in lieu of the coils I 8 and I8 of said Fig. 1 arrangement. Said coils l8 and I8 are made of a comparatively small number of turns, being connected in series with the primary coils II and 12 of the transformer. The coils 68 and 58 of the Fig. 4 construction are formed of a considerably greater number of turns than the number of turns in the coils II and I2, and such coils 88 and 89 are con- .nected in parallel with the coils II and I2 respectively rather than in series therewith. In the arrangement as shown in Fig. 4, the coils Ii and I2 are connected with the battery 14 by means of a lead 10; the coil It is connected with the standard 28 and the contact 21 by a lead 1|; the coil 88 is connected between the lead 10 and the lead 11 in parallel with the coil H by leads 12 and 13; the coil I2 is connected to the standard 30 and the contact 28 by a lead 14; the coil 69 is connected between the leads 18 and'14 in parallel with the coil 12 by leads 15; and the bars 22 and 22a are connected with the battery l4 by means of a lead 16, such lead 18 comprising a switch 11.

In the device of Fig. 4, the rectification is effected by the use of an auxiliary armature 81 formed of magnetic material and pivotally mounted at an intermediate point therealong at the end of the core Illa opposite to that at which the armature 28 is mounted. Such core I00. is provided with notches 88 and 88 in addition to the notches l5 and I5a, such notches 88 and 88 armature 81.

being located opposite the end portions of the I Said armature 8'! is provided with 'a plate of magnetic material on its upper face adjacent to the notch 89, serving to bring the right-hand end of the armature including said plate 98 into somewhat closer relation to the core Illa than that of the left-hand end of the armature in'the position of the parts as shown in said Fig. 4. Collars 9| of thin sheet copper are secured about the end portions of the armature 81 opposite the notches 88 and 89. Bars 92, 93. and 94 corresponding to the bars 2Ib, 22b and 23b of the arrangement as shown in Fig. 2 are provided, the bar 93 being provided with contact pieces 95 and 88 at its end portions adapted to engage set screws 91 and 98 adjustably mounted in standards 99 and I00 respectively. In the arrangement shown in said Fig. 4, the armature 81 is held at the limit of its movement in clockwise direction by a light spring IOI engaging a set screw I02 adjustably mounted in a standard I03. The parts are so arranged that the armature and its connected parts are substantially balanced with respect to the axis about which the armature is adapted to swing.

In this arrangement of Fig. 4, the standard 99 and the set screw 91 are electrically connected with the secondary coil 40 by a lead I04; the standard I00 and the set screw 98 are electrically connected with the secondary coil 4| by a lead and leads I06 and IN are connected respectively with the bar 93 and the coils 40 and I, said leads I06 and I0'I serving as the output leads for the high tension induced current impulses.

When the switch II of the Fig. 4 construction is closed, coils I2 and 69 are connected in parallel with each other with respect to the battery through the contacts 28 and 28, while coils II and 88 are connected in series with each other, with the coil II in transformer relationship to the coil I2. The coil 89 is connected so as to reenforce the field produced in the arm portion II by the coil I2. At the same time an induced current through the coil I I acting through the medium of the coil I 6 opposes the field in the arm portion I6 as set up by said coil I2. The field set up by the cooperating forces in the arm portion I1 is stronger than the field set up by the opposing forces in the arm portion IS, with the result that the armature-20 is polarized and is swung in clockwise direction in said Fig. 4. At the same time, a field is set up in the core Illa at the notches 88 and 89 and of the same polarity at both of said notches. This field in the core I0a sets up a field in the armature 81 whereby the armature is moved in counter-clockwise direction in said Fig. 4 by reason of the fact that the coupling is closer opposite the notch 89 than it is opposite the notch 88. As the armature 81 starts to swing in counter-clockwise direction, the influence of the field at the right is increased and the influence of the field at the left is decreased, with the result that by the time the circuit is broken between the contacts 96 and 98 at the right and a'new contact is effected between the parts 95 and 91 at the left the magnetic field is fully established in the armature 81 with opposite polarity at its end portions. This movement of the armature 81 takes place at precisely the same instant as that at which the movement of the armature 20 occurs in clockwise direction as above described.

Upon the opening of the circuit between the contacts 26 and 28 due to the clockwise movement of the armature 20, the reverse induced current impulse through the coil I2 and the battery current through the coil I I, brought about by the closing of the primary circuit at the contacts 25 and 21,, produces a changed polarity in the core I0a and in the core arms I6 and I1, serving to swing the polarized armature 20 in counterclockwise direction again to the position as shown in' said Fig. 4. At the same time, such changed polarity in the core I0a serves to repulse the armature 81 at the right opposite the notch 89 and to attract said armature 81 at the left opposite the notch 88 for swinging such armature 81 back to the position as-shown in said Fig. 4, such reaction upon the armature 81 being dependent upon the easy and quick change of the magnetic conditions in the core I0a and the comparatively much slower change in the magnetic conditions in the armature, this result being attained or at least greatly facilitated by the provision of the condensers 31, 88 and 39 in the battery circuits.

With the armatures 20 and 81 oscillating in unison but at all times in opposite directions, the circuits through the secondary coils 40 and 4| are alternately made and broken at precisely the same time that the circuits through the primary coils I I and I2 respectively are made and broken. The result is that the induced current impulses pass in one direction through the secondary coil 40 and in the opposite direction through the secondary coil 4 I, all of such impulses passing in the same direction through the output leads I08 and M1.

By the use of an auxiliary armature 81 as shown in Fig. 4, with the contacts for the secondary circuits on the auxiliary armature, as contrasted with the arrangement shown in Fig. 3, in which the contacts for both the primary and the secondary circuits are all on a single armature 20, I have provided for a more easy and a more certain adjustment of the parts to the desired working condition. In the arrangement shown in Fig. 4, the action of the auxiliary armature 81 is tuned with respect to a separate spring IOI from that effective in connection with the armature 20, giving a certain leeway with respect to the adjustment whichis not attained in the use of the construction of Fig. 3. Moreover, by the use of the two armatures, the pressure between the contacts is distributed to better advantage for obtaining the desired results.

In the arrangement shown in Fig. 5, the construction is similar to that shown in Fig. 4 except for the connection of the cooperating parts and the omission of the rectifying means. In the arrangement shown in said Fig. 5, the coil II is connected by a lead I8 with the standard 29 and contact 21; the bar 22 is connected with the battery It by a lead I9 including a switch 80;

battery lead 19 and is connected at its opposite end by a lead 84 with the standard 30 and contact 28. The coil 69 upon the arm portion I1 is connected at one end by a lead 85 to the battery lead I9 and is connected at its opposite end by a lead 88 to the standard 29 and contact 21.

In the arrangement as shown in said Fig. 5, when the switch 80 is closed, the coil I2 is connected with the battery I4 through the lead 82, the contacts 28 and' 26 and the lead I9. Under such circumstances the coil 68 is thrown out of effective operation since it is substantially short- 75 circuit between the contacts and 2?.

circuited by the metallic connection through the contacts 28 and 26: At the same time, the coil H and the coil 69 are connected through the leads 18, 86, 85, I9 and 8| with each other and with the battery l4. Inasmuch as the coil 69 has a very considerable number of turns, substantially all of the battery current will pass through the circuit comprising the coil l2 which is of very much lower resistance. The two principal forces effective under such circumstances are the primary current through the coil i2 and the induced current through the coils ii and 59, the coil 69 being connected in such relation that the induced current therethrough causes it to cooperate with the coil l2 in the establishment of strong magnetic field conditions in the arm portion l1. Under such circumstances, the armature 20 is polarized and is moved in clockwise direction in said Fig. 5, serving to open the circuit between the contacts 26 and 28 and to close the Upon the breaking of the circuit between the contac s 26 and 28, the reverse induced current through the coil I2 very quickly changes the direction of the flux in the core l0. When the circuit is closed between the contacts 25 and 2'1, the coil 69 is in effect short-circuited, and the coils i2 and 58 by the effect of the induced current therein serve to reenforce the effect of the battery current in the coil II for the establishment of a strong magnetic field in the arm portion IS. The result is that the armature 20 is quickly moved in counten-clockwise direction again to the position as shown in said Fig. 5, this result being effected so quickly that the polarity of the armature 253 is not changed.

In the operation of the deviceas shown in Fig. 5, the battery current through one of the primary coils H and I2 in opposition to the induced current through said primary coil serves to suppress oscillation so as to cut down the peaks of the current when the primary circuit is broken at the contacts. The result is that I have attained a smoother and more even current which is more fully serviceable for radio purposes.

I have found in practice in connection with devices of the several types shown in the drawings that satisfactory results are atta ned by the use of primary coils H and I2 of about or '70 turns each; that coils I8, I 9, 54 and 55 produce satisfactory results when provided with 12 to 20 turns each; and that satisfactory results are attained by the provision of 1500 to 2000 turns in each of the coils 68 and 69. In practice. I have atta ned satisfactory results by the provision of a straight bar armature made of silicon steel. Inasmuch as the armature in each instance is designed to retain its initial polarity, and since means is provided for insuring that this polarity shall be the same for succeeding periods of operation, it will be appreciated that each of the armatures may be in the form of a permanent magnet if such arrangement is desired.

While I prefer to employ the arrangement as shown in my drawings and as above described. it is to be understood that my invention is not to be limited thereto except so far as the claims may be so limited by the prior art.

I claim:

1. In a mechanism of the type described, the combination of an armature member having end pieces of magnetic material which are magnetically connected to each other, magnetic core parts adjacent to said end pieces toward which said 75 end pieces are movable, and means for producing changing magnetic field conditions involving changing polarity in said core parts adjacent to the end pieces of the armature for causing said armature to move alternately toward said core parts, said field producing means comprising coils on said core parts respectively, circuit means .ior connecting said coils with a source of electrical energy, and switch means controlled'by the movements of the armature for producing the re= quired changes in said circuit connections for causing said armature to be magnetically actuated successively in opposite directions, the arrangement being such that said end pieces of the armature have the same polarity throughout the operation of the device for insuring effective attraction and repulsion alternatively between the end pieces and the core parts.

2. In a mechanism of the type described, the combination oi an armature member pivotally mounted at an intermediate point and having end pieces of magnetic material at opposite ends, magnetic core parts adjacent to said end pieces toward which said armature is adapted to swing alternatively, yielding means adapted normally to hold said armature swung to the limit of its movement toward one of said core parts, and means for producing changing magnetic iield conditions involving changing polarity in said core parts adjacent to the end pieces of said armature for causing said armature to swing alternately toward said core parts in such rapid succession as to prevent a change in the polarity of the end pieces of said armature from that set up by the initial magnetization thereof, said field producing means comprising cells on said core parts respectively, circuit means for connecting said coils with a source of electrical energy, and switch means controlled by the swinging movement of said armature for producing the required changes in said circuit connections for causing said armature to be magnetically actuated successively in opposite directions.

3. In a mechanism of the type described, the

combination of an armature member pivotally mounted at an intermediate point and having pole pieces 01 magnetic material at opposite ends magnetically connected together for obtaining normally opposite polarity at the ends of the armature, magnetic core parts adjacent to said pole pieces of the armature toward which said armature is adapted to swing alternatively, yielding means adapted normally to hold said armature swung to the limit of its movement toward one of said core parts, coils on said core parts respectively, and circuit means for feeding electrical energy alternately to said coils for causing said armature to vibrate and comprising switch means controlled by the movement of the armature for producing the required changes in said circuit means for bringing about the vibratory movement of the armature.

4. In a mechanism of the type described, the combination of an armature member pivotally mounted at an intermediate point and having end pieces of magnetic material at opposite ends, magnetic core parts adjacent to said end pieces toward which said armature is adapted to swing alternatively, yielding means adapted normally to hold said armature swung to the limit of its movement toward one of said core parts, two coils on said core parts respectively, two other coils, circuit means connecting said second named two coils with said first named two coils respectively for feeding electrical energy alternately to said coils for causing" said armature to vibrate and comprising switch means controlled by the movement of the armature for producing the required changes in said circuit means for bringing about the vibratory movement of the armature, two other coils in transformer relationship to said second named two coils respectively, and circuit means connecting said third named two coils for permitting the flow of secondary currents by induction therethrough.

5. In a mechanism of the type described, the combination of an armature member pivotally mounted at an intermediate point and having end pieces of magnetic material at opposite ends, magnetic core parts adjacent to said end pieces toward which said armature is adapted to swing alternatively, yielding means adapted normally to hold said armature swung to the limit of its movement toward one of said core parts, contact pieces carried by said armature at its opposite end portions, other contact members mounted in position to engage said first named contact pieces alternatively as said armature is swung between the limits of its movements, coils on said core parts respectively, and circuit means connected with said contacts and with said coils for feeding electrical energy alternately to said coils and arranged whereby the magnetic fields set up successively in said core parts serve by magnetic action to swing said armature alternately in opposite directions.

6. In a mechanism of the type described, the combination of an armature member pivotally mounted at an intermediate point and having pole pieces of magnetic material at opposite ends magnetically connected together for obtaining normally opposite polarity at the ends of the armature, magnetic core parts adjacent to said pole pieces of the armature toward which said armature is adapted to swing alternatively. yielding means adapted normally to hold said armature swung to the limit of its movement toward one of said core parts, two coils on said core parts respectively, two other coils, circuit means connecting said second named two coils with said first named two coils respectively for feeding electrical energy alternately to said coils for causing said armature to, vibrate and comprising 'switch means controlled by the movement of the armature for producing the required changes in said circuit means for bringing about the vibra' tory movement of the armature, two other coils in transformer relationship to said second named two coils respectively, and circuit means conmeeting said third named two coils for permitting the flow of secondary currents by induction therethrough.

'7. In a mechanism of the type described, the combination of a shell type of core having a portion at one side at one and within which the densityof the field is considerably increased as compared with the remainder of the core when the normal magnetic field is set up in said core, coil means for producing an effective field in said core, an armature mounted at the end of said core and having a pole piece of magnetic material movable alternatively toward and from the core by magnetic action for eflectively cutting down the resistance to the flux at said point of increased density, an auxiliary coil mounted on said core adjacent to said portion of increased density tending when energized to produce a magnetic flux in said core adjacent to the coil independently of said first named coil means, and means for feeding current to said coils comprising switch means controlled by the swinging movements of tion of the core tending when energized to produce a magnetic flux in said outwardly directed arm portion independently of said first named coil means, and means for feeding current to the several coils comprising switch means controlled by the swinging movement of the armature whereby said coils by their cooperation produce a high frequency vibration of said armature.

9. In a mechanism of the type described, the combination of a shell type of core having a notch at each side of the core in its outer face at one end portion providing an outwardly di rected arm portion at each point, coil means for producing an effective field in said core as a whole, an armature member having end pieces of magnetic material which are magnetically connected to each other and which are located adjacent to said arm portions and are yieldingly movable toward and from the arm portions opposite said notches for decreasing the resistance to the flux across the notches, coils mounted on said arm portions respectively tending when energized to produce a magnetic flux in the arm portion independently of said first named coil means, and means for feeding current to the several coils comprising switch means controlled by the movements of the armature whereby said coils by their cooperation produce a vibration of said armature of such high frequency as to prevent a change in the polarity of the armature from that initially established therein.

10. In a mechanism of the type described, the combination of a. core, a coil on said core, an armature comprising an end piece of magnetic material movable yieldingly toward and from said core, means for feeding electrical energy intermittently to said coil for magnetizing the core and causing the armature to move toward and from the core, and circuit means of nonmagnetic material about said armatureproviding a closed circuit for the currents induced in the armature by reason of its movement through the magnetic field of said core,

11. In a mechanism of the type described. the combination of a core, coils on said core, an armature pivotally mounted at an intermediate point therealong so as to swing toward and from the core, bars mounted on said armature at opa resilient bar mounted on said armature adja- 75 cent to the pivotal axis of the armature, a second resilient bar mounted on said first named bar but extending toward the end of the annature beyond the end of the first named bar, a flexible bar mounted on said second resilient bar and extending toward the end 0! the armature but terminating short of the end of said second bar, a contact piece carried by said second resilient bar at a point beyond the ends of the other two bars, a contact member in position to be engaged by said contact piece when said second bar swings with said armature to the limit or" its movement away from the core, and means for feeding electrical energy to said coil means through said contact parts whereby an intermittent magnetic field in said core serves to swing the armature toward the core for breaking the engagement between said contact parts.

13. In a mechanism of the type described, the combination of a core, coil means on said core, two armatures pivotally mounted adjacent to said core so as to swing yieldingly toward the core, switch means controlled by the movement of one of said armatures, means for feeding current to said coil means through said switch means whereby an intermittent magnetic field is set up in said core for swinging both of said armatures toward the core at intervals and serving to open the circuit through said switch means, secondary coil means on said core in transformer relationship to said first named coil means, other switch. means controlled by the movement of the other one of said armatures. and means comprising connections between said secondary coil means and said other switch means whereby a unidirectional current is fed through said connections.

14. In a mechanism of the type described, the

combination of a shell type of core, two primary coils on the central leg of said core, two armatures adjacent to said core at opposite ends of the core respectively and each pivotally mounted at an intermediate point therealong so as to swing toward and from the core, means for holding each of said armatures yieldinglv at the limit of its motion in one direction. notches in the core opposite the end portions of each of said armatures, switch means controlled by the movement of one of said armatures. means for feeding current to said primary co ls alternately through said switch means whereby a magne ic flux is set up in said core in alternately opposite directions serving to swing both of said arma tures toward the core at intervals against the action of said yielding means. secondary coi s on said core in transformer relationship to said first named coils, other switch means controlled by the movement of the other one of said armatures. and means comprising connections between said secondary coils and said other switch means whereby said secondary coils are connected alternately in circuit for the flow of induced currents therethrough and whereby the induced current impulses through both of said coils flow in the same direction through a portion of said circuit connections.

15. In a mechanism of the type described, the combination of an armature member having end pieces of magnetic material which are magnetically connected to each other, magnetic core parts adjacent to said end pieces toward which said end pieces are yieldingly movable, coils on said core parts for producing changing magnetic field conditionsinvolving changing polarity in said-core parts adjacent to the end pieces of the armature for causing said armature to move alternately toward said core parts, secondary coils in transformer relation to said first named coils on said core parts, and means for feeding current to said first named coils and for connecting said secondary coils in closed circuits in such arrangement as to cause said armature to move alternately toward said core parts at such high frequency as to prevent the end pieces of the armature from changing polarity from that first established therein, and comprising switch means for the primary circuits and other switch means for the secondary circuits controlled by "the movements of the armature for producing the required changes in the primary circuit connections for causing said armature to be magneticah ally actuated successively in opposite directions and the required changes in the secondary circuit connections for insuring that the induced currents from said secondary coils shall flow in the same direction through the output leads oi the secondary circuit means.

16. In a mechanism of the type described, the combination of a shell type of core having a notch at each side of the core in its outer face at one end portion providing an outwardly directed arm portion at each point, coil means for producing an effective field in said core as a whole, n armature member pivotally mounted at in" mediate point and having end pieces; of g netic material at opposite ends opposite notches and magnetically connected to each other, with each of said end pieces in position to decrease the resistance to the has across one of said notches when the armature swings toward that notch, yielding means adapted normally to hold said armature swung to the limit of its movement toward one of said arm portions, coiis mounted on said arm portions respectively each tending when energized to produce a magnetic flux in the'arm portion independently of said. first named coil means, means for feeding current to the several coils comprising switch means controlled by the movement of the armature whereby said coils by their cooperation produce a vibration of said armature, condenser means connected across the switch means at each end of the armature, secondary coils in transformer relationship to said first named coils, and means for connecting said secondary coils in closed circuits and comprising switch means controlled by a the movement of the armature and operating for shifting the connections in said secondary circuits in such manner as to insure that the induced currents from said secondary coils flow in the same direction through the output leads of said secondary circuit means.

1'7. In a mechanism of the type described, the combination oi. a core, a coil on said core, an armature comprising an and piece of magnetic material movable yieldingly toward and from said core, and means for feeding electrical energy intermittently to said coil for magnetizing the core and causing the armature to move toward and from the core, said feeding means comprising a switch 'in the form of a contact piece of tungsten cooperating with a contact formed of molybdenum, with one of said contact parts movable with the armature for making and breaking the circuit.

18. In a mechanism of the type described, the combination of a core bar, coil means on said core bar, core means providing an all-metal retu'rn path for the flux threading said coil means, other return path means connecting the end portions of said core bar and providing greatly increased resistance to magnetic flux at one point as compared with the principal remaining portions, an armature member comprising a pole piece of magnetic metal movable toward and from said second named return path means at said point of increased resistance serving as an auxiliary core part for bridging said portion of increased resistance, circuit means comprising switch means operated by said armature member serving to connect said coil means periodically with a source of electrical energy for establishing a flux at intervals in said core for moving said pole piece by magnetic attraction periodically toward the core, and other coil means adjacent to a magnetic metal portion of said armature member connected by said circuit and switch means alternatively with a source of electrical energy serving after each movement of said pole piece toward said core means to move the armature member by magnetic attraction in the opposite direction for carrying said pole piece away from the core.

19. In a mechanism of the type described, the combination of a core bar, two coils on said core bar, core means providing an ail-metal return path for the flux threading said coils, other return path means connecting the end portions 01' said core bar and providing greatly increased resistance to magnetic flux at one point as compared with the principal remaining portions, an armature member comprising a pole piece of magnetic metal movable toward and-from said second named return path means at said point of increased resistance serving as an auxiliary core part for bridging said portion or increased resistance, circuit means comprising switch means operated by said armature member serving to connect said two coils alternatively with a. source of electrical energy for establishing a flux alternately in opposite directions in said core serving with the flux in one direction to move said pole piece by magnetic attraction toward the core, and other coil means adjacent to a magnetic metal portion of said armature member connected by said circuit and switch means with a source of electrical energy for energization concurrently with one oi' said first named coils serving after each movement or said pole piece toward said core means to move the armature member by magnetic attraction in the opposite direction :ior carrying said pole piece away from the core.

STEPHEN F. JAIHES. 

